JPWO2021064810A5 - - Google Patents

Description

The present invention relates to a stretch detection device that electrically detects stretch deformation of a base material.

Conventionally, an expansion / contraction detection device that electrically detects expansion / contraction deformation has been proposed. The expansion / contraction detection device detects based on changes in capacitance and electrical resistance due to expansion / contraction of the expansion / contraction material, such as the abdominal circumference fluctuation measuring device disclosed in Utility Model Registration No. 3208866 (Patent Document 1). It is equipped with a stretch sensor that detects the deformation of the object.

By the way, the detection unit of the stretch sensor in Patent Document 1 electrically detects the expansion and contraction deformation of the base material by stretching and deforming following the base material provided with the detection unit. Specifically, for example, the detection unit is configured by a capacitor in which electrodes are fixed on both sides of the dielectric layer, and the dielectric layer is deformed according to the expansion and contraction deformation of the base material to form the detection unit. The capacitance of the capacitor is changed. Then, by detecting the presence or absence of expansion and contraction deformation of the base material and the amount of expansion and contraction deformation based on the capacitance value of the detection unit, the deformation of the detection target and the like are detected.

Utility Model Registration No. 3208866 Gazette

However, as a result of the study by the present inventor, in the structure in which the detection portion is deformed following the base material as in Patent Document 1, there is a possibility that accurate detection may not be possible when the amount of elongation and deformation of the base material is large. .. That is, when the detection unit that can follow the elongation deformation of the base material undergoes a large elongation deformation due to the large elongation deformation of the base material, the electrical resistance becomes remarkable due to the excessive deformation of the electrode that outputs the electrical change of the detection unit. As the size increases, the detection accuracy may decrease or the detection itself may become impossible.

An object of the present invention is to provide an expansion / contraction detection device having a novel structure capable of accurately detecting a large expansion / contraction deformation.

Hereinafter, preferred embodiments for grasping the present invention will be described, but each of the embodiments described below is described as an example, and not only can be appropriately combined with each other and adopted, but also described in each embodiment. The plurality of components of the above can be recognized and adopted independently as much as possible, and can be appropriately adopted in combination with any of the components described in another embodiment. Thereby, in the present invention, various other embodiments can be realized without being limited to the embodiments described below.

In the first aspect, in a thin-walled base material that can be expanded and contracted in the plane direction, a detection unit that expands and contracts following the expansion and contraction of the base material and electrically detects the expansion and contraction of the base material. It is an expansion / contraction detection device provided,
The detection unit has a structure in which detection electrodes are superposed on both sides of the dielectric layer, and static electricity detects expansion and contraction of the dielectric layer due to expansion and contraction of the base material based on a change in capacitance. While it is said to be a capacitive sensor,
The base material has a high expansion / contraction portion and a low expansion / contraction portion, and the expansion / contraction deformation rate of the low expansion / contraction portion in the substrate is made smaller than that of the high expansion / contraction portion.
The detection electrode is provided on the highly stretchable portion in which the base material extends linearly in the length direction with a substantially constant width dimension and on the end side in the length direction of the highly stretchable portion. It is provided so as to straddle the low expansion / contraction portion extending in a cross-sectional shape larger than the portion, and the detection electrode extends only from the low expansion / contraction portion to the middle portion in the length direction of the high expansion / contraction portion . be.

According to the expansion / contraction detection device having a structure according to this embodiment, the detection unit is provided in the low expansion / contraction portion of the base material having a low expansion / contraction deformation rate, so that the detection unit is provided even when the deformation amount of the entire base material is large. The amount of deformation of the part to be deformed is suppressed. Therefore, even when the base material is significantly deformed, the detection unit can accurately detect the expansion and contraction deformation of the base material by preventing the detection unit from excessively increasing the electric resistance due to the large deformation. Further, according to the expansion / contraction detection device having a structure according to this aspect, when the expansion / contraction deformation amount of the base material is large, the detection unit is also located in the low expansion / contraction part, so that the expansion / contraction deformation amount of the entire detection unit is obtained. Is suppressed, and deterioration of detection performance due to excessive deformation of the detection unit is prevented. Further, when the amount of expansion / contraction deformation of the base material is small, the high expansion / contraction portion is deformed relatively large, so that the detection sensitivity can be improved by the detection unit located in the high expansion / contraction portion. Further, according to the expansion / contraction detection device having a structure according to this embodiment, the capacitance between the detection electrodes and the detection electrodes facing each other across the dielectric layer due to the deformation of the detection electrode and the dielectric layer due to the expansion / contraction deformation of the base material. Changes. Based on the electrical output of this change in capacitance, the amount of expansion and contraction deformation of the base material can be accurately detected.

The second aspect is that in the expansion / contraction detection device described in the first aspect, the dielectric layer is composed of the base material .

According to the expansion / contraction detection device having a structure according to this aspect, the number of parts can be reduced because the base material also serves as a dielectric layer.

The third aspect is that in the expansion / contraction detection device according to the first or second aspect, the high expansion / contraction portion and the low expansion / contraction portion are made of the same material.

According to the expansion / contraction detection device having a structure according to this aspect, for example, it is possible to integrally form the entire base material provided with the high expansion / contraction portion and the low expansion / contraction portion.

In the fourth aspect, in the expansion / contraction detection device according to any one of the first to third aspects, the width dimension of the low expansion / contraction portion is made larger than the width dimension of the high expansion / contraction portion. ..

According to the expansion / contraction detection device having a structure according to this aspect, the low expansion / contraction portion and the high expansion / contraction portion can be set in the base material depending on the difference in width dimension. For example, when the low-stretchable portion and the high-stretchable portion are formed of the same material as in the third aspect, the difference in the stretch ratio between the low-stretchable portion and the high-stretchable portion can be easily set by the difference in the width dimension. Can be done.

Further, for example, when a plurality of detection portions such as an electrode layer and a dielectric layer are laminated, the high expansion / contraction portion and the low expansion / contraction portion do not affect the laminated structure due to the dimensions in the width direction orthogonal to the stacking direction. The expansion and contraction part can be set.

A fifth aspect is the expansion / contraction detection device according to any one of the first to fourth aspects, wherein the thickness dimension of the low expansion / contraction portion is larger than the thickness dimension of the high expansion / contraction portion. Is.

According to the expansion / contraction detection device having a structure according to this aspect, the low expansion / contraction portion and the high expansion / contraction portion can be set in the base material depending on the difference in thickness and dimension. For example, when the low-stretchable portion and the high-stretchable portion are formed of the same material as in the third aspect, the difference in the stretch ratio between the low-stretchable portion and the high-stretchable portion is easily set by the difference in the thickness dimension. be able to.

In the sixth aspect, in the expansion / contraction detection device described in any one of the first to fifth aspects, the output value of the detection signal output by the detection unit in response to the expansion / contraction deformation of the base material is assumed. It does not have a maximum value in the range of expansion and contraction deformation of the base material.

According to the expansion / contraction detection device having a structure according to this embodiment, for example, it is possible to prevent a measurement error of expansion / contraction deformation caused by the output value of the detection signal being the same on both sides of the maximum value.

A seventh aspect is the expansion / contraction detection device according to any one of the first to sixth aspects, in which the connection portion of the wiring to the detection unit is arranged in the low expansion / contraction portion.

According to the expansion / contraction detection device having a structure according to this aspect, it is difficult to allow large deformation of the connection portion of the wiring such as the output lead wire because it is soldered or a connector is provided. Therefore, by providing the connection portion of the wiring in the low expansion / contraction portion where the expansion / contraction deformation is suppressed, the stress acting on the connection portion of the wiring at the time of expansion / contraction deformation of the base material is reduced, and the reliability and durability are improved. ..

The eighth aspect is the expansion / contraction detection device according to the seventh aspect, wherein the connection portion includes a wiring fixing member that partially sandwiches and restrains the low expansion / contraction portion in the thickness direction. Is.

According to the expansion / contraction detection device having a structure according to this aspect, the expansion / contraction deformation of the detection unit is further reduced at the connection portion of the wiring by restraining the low expansion / contraction portion by the wiring fixing member. Therefore, the stress acting on the connection portion of the wiring when the base material is deformed is further reduced, and the durability is further improved. Further, in the ninth aspect, in the expansion / contraction detection device according to any one of the first to eighth aspects, the width dimension between the facing surfaces of the detection electrodes superposed on both sides of the dielectric layer is set. The high expansion / contraction portion is smaller than the low expansion / contraction portion. Further, in the tenth aspect, in the expansion / contraction detection device according to any one of the first to ninth aspects, the wiring conducted to the detection electrode is connected to the low expansion / contraction portion. ..

According to the present invention, large expansion and contraction deformation can be accurately detected.

A plan view showing a telescopic sensor as the first embodiment of the present invention. II-II sectional view of FIG. Section III-III sectional view of FIG. IV-IV sectional view of FIG. VV cross-sectional view of FIG. An exploded perspective view of the telescopic sensor shown in FIG. Bottom view of the first fixing member mounted on the telescopic sensor shown in FIG. Top view of the second fixing member mounted on the telescopic sensor shown in FIG. A cross-sectional view illustrating a state in which the wiring fixing member is attached to the expansion / contraction sensor shown in FIG. A graph illustrating the relationship between the output value of the expansion / contraction sensor shown in FIG. 1 and the expansion / contraction deformation amount of the expansion / contraction sensor. A plan view showing a sensor main body constituting the expansion / contraction detection device as the second embodiment of the present invention. A vertical sectional view showing a telescopic sensor as a third embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIGS. 1 to 5 show a stretch sensor 10 as a first embodiment of a stretch detection device having a structure according to the present invention. The expansion / contraction sensor 10 includes a sensor body 12, and as shown in FIGS. 2 to 6, the sensor body 12 has a first electrode 16 and a second electrode 18 as detection electrodes on both surfaces of the dielectric layer 14. Has a structure provided with. In the following description, as a general rule, the vertical direction is the vertical direction in FIG. 2, which is the thickness direction, and the length direction is the horizontal direction in FIG. 1, which is the detection direction of the expansion / contraction deformation by the expansion / contraction sensor 10. The direction means the vertical direction in FIG. 1, respectively.

As the dielectric layer 14, elastic rubber or resin elastomer is adopted, and preferably one having a relatively large relative permittivity is adopted. Specifically, for example, urethane rubber, silicone rubber, nitrile rubber, hydride nitrile rubber, acrylic rubber, natural rubber, isoprene rubber, ethylene-propylene rubber, chloroprene rubber, chlorinated polyethylene, chlorosulfonated polyethylene and the like are adopted. Ru.

The dielectric layer 14 has a thin strip shape as a whole, and has elasticity in the plane direction (direction substantially parallel to the surface). In the dielectric layer 14, the central portion in the length direction is a narrow high expansion / contraction portion 20, and both end portions in the length direction are wide low expansion / contraction portions 22, 22.

The high expansion / contraction portion 20 has a substantially rectangular sheet shape. That is, the high expansion / contraction portion 20 extends linearly in the length direction with a substantially constant width dimension and thickness dimension. The high expansion / contraction portion 20 has a smaller dimension in the width direction than the low expansion / contraction portion 22 described later.

The low expansion / contraction portion 22 is provided with a tapered widening portion 24 whose width dimension gradually increases toward the outside in the length direction, and the width direction dimension is larger than that of the high expansion / contraction portion 20. The widening portion 24 of the present embodiment has a shape in which the rate of change in the width dimension changes in the length direction and is smoothly connected to the high expansion / contraction portion 20, so that stress concentration is unlikely to occur due to a sudden change in the width dimension. Has been done.

When the dielectric layer 14 expands and contracts in the length direction due to the action of an external force, the amount of expansion and contraction deformation of the high expansion and contraction portion 20 and the low expansion and contraction portion 22 are different from each other. That is, the high expansion / contraction portion 20 and the low expansion / contraction portion 22 are made of the same material, and the thickness dimensions are substantially the same, and the width dimension of the low expansion / contraction portion 22 is larger than that of the high expansion / contraction portion 20. There is. Therefore, the low expansion / contraction portion 22 has a smaller expansion / contraction deformation amount in the length direction than the high expansion / contraction portion 20. The low expansion / contraction portion 22 has a smaller expansion / contraction deformation rate in the length direction with respect to an input (unit force) of the same magnitude than the high expansion / contraction portion 20. The stretch deformation rate in the length direction is an index showing the ease of stretch deformation in the length direction, and is the original length dimension (force is applied) when stretching and deforming by applying a unit force in the length direction. It is the ratio of the length dimension after expansion and contraction to the length dimension in the initial state. In the present embodiment, when a force in the length direction is applied to the dielectric layer 14 having the high expansion / contraction portion 20 and the low expansion / contraction portion 22 having different expansion / contraction deformation rates arranged side by side in the length direction, the low expansion / contraction portion 22 expands and contracts. The length dimension of the high expansion / contraction portion 20 and the low expansion / contraction portion 22 in the initial state and the expansion / contraction deformation rate of the high expansion / contraction portion 20 and the low expansion / contraction portion 22 are set so that the deformation amount is smaller than the expansion / contraction deformation amount of the high expansion / contraction portion 20. It is set.

The first and second electrodes 16 and 18 are provided in a laminated state at one end of the dielectric layer 14 in the length direction. The first and second electrodes 16 and 18 are in the form of a thin film having elasticity in the plane direction. The first and second electrodes 16 and 18 are formed of, for example, a conductive elastomer in which a conductive filler is mixed with a rubber or a resin elastomer and scattered. As the rubber or resin elastomer constituting the first and second electrodes 16 and 18, the same material as that of the dielectric layer 14 can be adopted. As the conductive filler constituting the first and second electrodes 16 and 18, for example, carbon black, carbon nanotubes, powder of conductive metal and the like can be adopted.

The first and second electrodes 16 and 18 are formed by, for example, directly adhering the forming material as described above to one of the front and back surfaces of the dielectric layer 14. The first and second electrodes 16 and 18 are strip-shaped thin films extending in the length direction as a whole, and an inclined portion 26 inclined in the width direction is provided in an intermediate portion in the length direction. The outside of the inclined portion 26 in the length direction of the dielectric layer 14 is a conducting portion 28 having a relatively narrow width. The inside of the dielectric layer 14 above the inclined portion 26 in the length direction is a relatively wide sensor component portion 30.

As shown in FIG. 1, the conductive portion 28a of the first electrode 16 and the conductive portion 28b of the second electrode 18 are located apart from each other in the width direction.

The inclined portion 26a of the first electrode 16 and the inclined portion 26b of the second electrode 18 are inclined to the opposite sides in the width direction, and as shown in FIGS. 1 to 3, the sensor configuration of the first electrode 16 The portion 30a and the sensor component portion 30b of the second electrode 18 are provided at positions where they overlap each other with the dielectric layer 14 interposed therebetween. Then, in a portion where the sensor component 30a of the first electrode 16 and the sensor component 30b of the second electrode 18 face each other in the thickness direction with the dielectric layer 14 interposed therebetween, the dielectric is dielectric based on the change in capacitance. A detection unit 32 as a capacitance type sensor element that electrically detects the amount of deformation of the body layer 14 is configured. The detection unit 32 is a capacitor composed of a sensor component 30a of the first electrode 16, a sensor component 30b of the second electrode 18, and a dielectric layer 14, and includes the dielectric layer 14. It is said that it can be deformed by following the expansion and contraction deformation of the base material 38, which will be described later.

The detection unit 32 is provided so as to straddle the high expansion / contraction portion 20 and the low expansion / contraction portion 22, and the inner portion in the length direction of the expansion / contraction sensor 10 is provided in the high expansion / contraction portion 20 of the dielectric layer 14 and is long. The outer portion in the radial direction is provided on the low expansion / contraction portion 22 of the dielectric layer 14. In the detection unit 32, the length dimension of the portion provided in the high expansion / contraction portion 20 and the length dimension of the portion provided in the low expansion / contraction portion 22 are not particularly limited, but are substantially the same in the present embodiment. The area of the detection unit 32 in the vertical direction is larger in the portion provided in the high expansion / contraction portion 20 than in the portion provided in the low expansion / contraction portion 22. As a result, in the detection value of the capacitance in the detection unit 32, the influence of the detection value of the portion provided in the low expansion / contraction unit 22 becomes larger than the influence of the detection value of the portion provided in the high expansion / contraction unit 20.

The upper surface of the sensor body 12 having such a structure is covered with a first protective layer 34. The first protective layer 34 is made of a material having elasticity and electrical insulation. The first protective layer 34 of the present embodiment is made of the same material as the dielectric layer 14. The first protective layer 34 has substantially the same outer shape as the dielectric layer 14. The first protective layer 34 is overlapped and fixed to the upper surface of the sensor main body 12.

The lower surface of the sensor body 12 is covered with a second protective layer 36. The second protective layer 36 is made of a material having elasticity and electrical insulation like the first protective layer 34, and in the present embodiment, the dielectric layer 14 and the first protective layer 34 are combined with each other. It is made of the same material. The second protective layer 36 has substantially the same outer shape as the dielectric layer 14 and the first protective layer 34. The second protective layer 36 is overlapped and fixed to the lower surface of the sensor main body 12.

The first protective layer 34 and the second protective layer 36 are shown independently of the dielectric layer 14 in FIGS. 2 and 3, but for example, the boundary portion overlapped with the dielectric layer 14 by heat welding. May be melted and integrated. The base material 38 of the present embodiment is composed of a dielectric layer 14 and first and second protective layers 34 and 36. In other words, the expansion / contraction sensor 10 of the present embodiment is entirely made of the base material 38 except for the first and second electrodes 16 and 18. Therefore, the high expansion / contraction portion 20 is provided not in the central portion in the length direction of only the dielectric layer 14 but in the central portion in the length direction of the base material 38 including the first and second protective layers 34 and 36. Similarly, the low expansion / contraction portion 22 is provided not at both ends in the length direction of the dielectric layer 14 alone, but at both ends in the length direction of the base material 38 including the first and second protective layers 34 and 36. ing. The expansion and contraction deformation rate of the high expansion and contraction portion 20 and the low expansion and contraction portion 22 is defined as the expansion and contraction deformation rate of the high expansion and contraction portion 20 and the low expansion and contraction portion 22 in the base material 38 including the first and second protective layers 34 and 36. To.

As shown in FIGS. 1 and 2, the end portion of the conductive portion 28a of the first electrode 16 is exposed downward through the first conductive hole 40 penetrating the dielectric layer 14 and the second protective layer 36. There is. The end of the conductive portion 28b of the second electrode 18 is exposed downward through the second conductive hole 42 penetrating the second protective layer 36. Further, in the portions where the conductive portions 28a of the first electrode 16 and the conductive portions 28b of the second electrode 18 are separated from each other on both sides in the width direction, the dielectric layer 14 and the first and second protective layers 34 and 36 are formed. Two locking holes 44 are formed so as to penetrate in the thickness direction.

In the expansion / contraction sensor 10 having such a structure, the first wiring 46 is connected to the conductive portion 28a of the first electrode 16, and the second wiring 48 is connected to the conductive portion 28b of the second electrode 18. It is connected. The first and second wirings 48 apply a detection voltage to the detection unit 32 and output the capacitance of the detection unit 32 to an external detection device (not shown).

The first and second wirings 46 and 48 are connected to the conduction portions 28a and 28b of the first and second electrodes 18 by the wiring fixing member 50. The wiring fixing member 50 is composed of a first fixing member 52 shown in FIG. 7 and a second fixing member 54 shown in FIG.

The first fixing member 52 is an electrically insulating member made of a hard synthetic resin or the like. The specific shape of the first fixing member 52 is not particularly limited, but the first fixing member 52 of the present embodiment has a substantially rectangular flat plate shape. A pressing portion 56 is provided on the lower surface of the first fixing member 52. The pressing portion 56 is formed of, for example, an elastic body such as rubber, and projects downward from the lower surface of the first fixing member 52. At each of the four corners of the first fixing member 52, a square columnar first fitting portion 58 extending downward is provided.

The second fixing member 54 is an electrically insulating member made of a hard synthetic resin or the like. The second fixing member 54 has a substantially rectangular flat plate shape corresponding to the first fixing member 52. At the four corners of the second fixing member 54, a second fitting portion 60 having a square columnar shape extending downward is provided.

On the upper surface of the second fixing member 54, the first connection electrode 62 to which the first wiring 46 is connected and the second connection electrode 64 to which the second wiring 48 is connected are separated from each other. It is provided. Two locking projections 66 projecting upward from the second fixing member 54 are provided on both sides of the first connection electrode 62 and the second connection electrode 64 in the width direction (left-right direction in FIG. 8). It is provided.

The wiring fixing member 50 is attached to one end of the expansion / contraction sensor 10 in the length direction. That is, the first fixing member 52 is overlapped with respect to the expansion / contraction sensor 10 from above, and the second fixing member 54 is overlapped with respect to the expansion / contraction sensor 10 from below, and the first fixing member 52 and the first fixing member 52 are overlapped with each other. The second fixing member 54 is fixed to each other. The first fixing member 52 and the second fixing member 54 are formed by fitting the first fitting portion 58 of the first fixing member 52 to the second fitting portion 60 of the second fixing member 54. , Are fixed to each other.

Further, the locking projection 66 of the second fixing member 54 is inserted into the locking hole 44 of the expansion / contraction sensor 10, and the expansion / contraction sensor 10 is positioned with respect to the second fixing member 54 in the length direction. As a result, the wiring fixing member 50 is attached to the end portion of the expansion / contraction sensor 10 in the length direction. Since the wiring fixing member 50 is attached to the low expansion / contraction portion 22 of the expansion / contraction sensor 10, the position of the wiring fixing member 50 is displaced with respect to the wiring fixing member 50 due to the deformation of the expansion / contraction sensor 10, and the expansion / contraction sensor at the portion locked with the wiring fixing member 50. 10 damage and the like are prevented.

As shown in FIG. 9, in the state where the wiring fixing member 50 is attached to the expansion / contraction sensor 10, the first connection electrode 62 provided on the second fixing member 54 is a conduction of the first electrode 16 of the expansion / contraction sensor 10. It is superposed on the portion 28a in a contact state through the first conduction hole 40. Further, the second connection electrode 64 provided on the second fixing member 54 is superposed on the conduction portion 28b of the second electrode 18 of the expansion / contraction sensor 10 in a contact state through the second conduction hole 42. As a result, the first wiring 46 is connected to the first electrode 16 in a conductive state, and the second wiring 48 is connected to the second electrode 18 in a conductive state. Therefore, each connection portion of the first electrode 16 and the first wiring 46 and the second electrode 18 and the second wiring 48 is arranged in the low expansion / contraction portion 22 of the base material 38, and the first, first, It is configured to include a wiring fixing member 50 including a second connection electrode 62, 64.

The pressing portion 56 provided on the first fixing member 52 of the wiring fixing member 50 is pressed against the portions of the expansion / contraction sensor 10 provided with the conductive portions 28a and 28b of the first and second electrodes 16 and 18. .. As a result, the conductive portions 28a and 28b are elastically pushed toward the first and second connection electrodes 62 and 64 by the pressing portion 56, and the first and second electrodes 16 and 18 and the first and second electrodes 16 and 18 are used. The connection electrodes 62 and 64 are kept in contact with each other.

The low expansion / contraction portion 22 is partially constrained by being sandwiched between the pressing portion 56 and the first and second connection electrodes 62 and 64, and almost no deformation occurs in the constrained portion. This prevents problems such as disconnection due to deformation of the base material 38 at the connection portion between the first and second electrodes 16 and 18 and the first and second wirings 46 and 48.

As shown in FIG. 1, a mounting member 68 is mounted on the other end of the expansion / contraction sensor 10 in the length direction. The specific structure of the mounting member 68 is not particularly limited, but is composed of, for example, a member corresponding to the first fixing member 52 and the second fixing member 54 of the wiring fixing member 50. Since there is no electrode at the other end of the expansion / contraction sensor 10, the mounting member 68 does not have to be provided with members corresponding to the first and second connecting electrodes 62 and 64 and the pressing portion 56. Further, the mounting member 68 may not have the locking projection 66, but if the locking projection 66 is provided, the mounting member 68 is composed of parts common to the first and second fixing members 52 and 54. be able to.

By attaching the wiring fixing member 50 and the mounting member 68 mounted at both ends in the length direction to a detection target (not shown), the expansion / contraction sensor 10 is located between the wiring fixing member 50 and the mounting portion of the mounting member 68 in the detection target. The change in distance (expansion and contraction deformation) is electrically detected. The expansion / contraction sensor 10 of the present embodiment can not only detect expansion / contraction deformation but also measure the amount of expansion / contraction deformation, and can detect the amount of change in the distance between the wiring fixing member 50 and the attachment portion of the attachment member 68 in the detection target. It can be measured electrically. Both ends of the expansion / contraction sensor 10 are attached to the detection target. Since this mounting portion is composed of the low expansion / contraction portion 22, the amount of deformation is reduced. The distance between the wiring fixing member 50 and the mounting portion of the mounting member 68 in the detection target here does not necessarily mean only the shortest distance between the two points. For example, the expansion / contraction sensor 10 is placed on the curved surface of the detection target. When attached, it refers to the length of the path along the surface.

That is, when the detection voltage is applied between the first electrode 16 and the second electrode 18, and the distance between the wiring fixing member 50 and the mounting portion of the mounting member 68 in the detection target changes, the expansion / contraction sensor 10 In, expansion and contraction deformation in the surface direction occurs between the wiring fixing member 50 and the mounting member 68. As a result, in the detection unit 32 of the expansion / contraction sensor 10, expansion / contraction deformation in the surface direction and accompanying expansion / contraction deformation in the thickness direction occur. As a result, the area of the facing portions of the first and second electrodes 16 and 18 and the distance between the facing portions of the first and second electrodes 16 and 18 change, and the capacitance of the detection unit 32 changes. .. Then, by calculating the amount of expansion / contraction deformation of the expansion / contraction sensor 10 corresponding to the change in the capacitance value of the detection unit 32 by an external detection device (not shown), the expansion / contraction or bending of the detection target to which the expansion / contraction sensor 10 is attached, etc. The amount of deformation of can be measured. As described above, the expansion / contraction sensor 10 detects the amount of deformation to be detected based on the change in the capacitance of the detection unit 32 due to the expansion / contraction deformation of the dielectric layer 14 constituting the base material 38. In short, the expansion / contraction sensor 10 detects the deformation of the detection target by detecting the expansion / contraction deformation of the base material 38 that follows the deformation of the detection target.

For the calculation of the expansion / contraction deformation amount of the expansion / contraction sensor 10 by the external detection device, for example, the expansion / contraction deformation amount of the expansion / contraction sensor 10 corresponding to the change in the capacitance value of the detection unit 32 is used as map data in the external detection device. It is realized by storing in advance and reading the expansion / contraction deformation amount of the expansion / contraction sensor 10 corresponding to the capacitance value output from the detection unit 32 from the map data.

The expansion / contraction sensor 10 may be attached to the detection target in a non-deformed state to detect the deformation or movement of the detection target by the extension deformation, or may be attached to the detection target in the extension / deformation state in advance. The deformation or movement of the detection target may be detected by the contraction deformation.

When the amount of elongation deformation in the length direction of the expansion / contraction sensor 10 is small, the expansion / deformation amount of the low expansion / contraction portion 22 is particularly small in the portion provided in the low expansion / contraction portion 22 in the detection unit 32, so that the expansion deformation is detected. It can be difficult to do. However, in the portion of the detection unit 32 provided in the high expansion / contraction portion 20, the expansion deformation amount of the high expansion / contraction portion 20 is relatively large, so that the expansion deformation can be detected. Therefore, since a part of the detection unit 32 is provided in the high expansion / contraction unit 20, the detection sensitivity of the expansion / contraction sensor 10 is improved, and it becomes possible to accurately detect smaller expansion / contraction deformation.

When the amount of expansion and deformation of the expansion and contraction sensor 10 in the length direction is large, the amount of expansion and deformation of the high expansion and contraction portion 20 is particularly large in the portion provided in the high expansion and contraction portion 20 in the detection unit 32, so that the expansion and deformation amount is large. The electrical resistance of the first and second electrodes 16 and 18 becomes extremely large, and it may be difficult to detect elongation deformation. However, in the portion of the detection unit 32 provided in the low expansion / contraction portion 22, the amount of elongation deformation of the low expansion / contraction portion 22 is relatively small, so that the deformation of the first and second electrodes 16 and 18 is suppressed. , Stretching deformation can be detected. Therefore, since a part of the detection unit 32 is provided in the low expansion / contraction unit 22, a larger expansion / deformation can be detected by the expansion / contraction sensor 10.

The reason why the electric resistance of the first and second electrodes 16 and 18 is remarkably increased by the large elongation deformation is that, for example, the first and second electrodes 16 and 18 are a conductive elastomer in which a conductive filler is mixed with the elastomer. (Conductive rubber) is considered. That is, the electric resistance (conductivity) of the conductive elastomer is affected by the distance between the conductive fillers dispersed in the elastomer. Therefore, when the first and second electrodes 16 and 18 are elongated and deformed in the length direction which is the energization direction, the distance between the conductive fillers becomes long and the electric resistance increases. Since the increase in electrical resistance corresponds to the amount of deformation of the first and second electrodes 16 and 18, when the first and second electrodes 16 and 18 are greatly deformed following the deformation of the high expansion / contraction portion 20. In some cases, the electrical resistance of the first and second electrodes 16 and 18 becomes significantly large, and the conductivity is substantially lost.

As described above, in the expansion / contraction sensor 10 of the present embodiment, since the detection unit 32 is provided so as to straddle the high expansion / contraction portion 20 and the low expansion / contraction portion 22, the expansion / contraction deformation in a wide range from smaller deformation to larger deformation Can be detected accurately.

As shown in the graph of FIG. 10A, the output value of the detection signal output by the detection unit 32 of the expansion / contraction sensor 10 as an embodiment is the range of the expected expansion / contraction deformation amount of the expansion / contraction sensor 10, in other words, expansion / contraction. Within the range of the amount of expansion and contraction deformation of the object to be detected by the sensor 10, the output value of the detection signal increases as the amount of expansion and contraction deformation increases without having an extreme value. On the other hand, in the comparative example in which the entire structure corresponds to the high expansion / contraction portion 20, the resistance values of the first and second electrodes 16 and 18 increase as the amount of expansion / contraction deformation increases, and the apparent output value increases. Go down. As a result, as shown in the graph of FIG. 10B, it has a maximum value in the range of the expected expansion / contraction deformation amount of the expansion / contraction sensor 10, and the expansion / contraction deformation amount is uniquely obtained from the output value of the detection signal. It can be difficult to ask. As described above, the expansion / contraction sensor 10 as an embodiment can effectively detect even a larger expansion / contraction deformation amount by providing the detection unit 32 in the low expansion / contraction unit 22.

In the first and second electrodes 16 and 18, the conductive portions 28a and 28b are provided so as to be connected to the portions provided in the low expansion / contraction portion 22 in the sensor constituent portions 30a and 30b. Therefore, even if the expansion / contraction deformation amount of the expansion / contraction sensor 10 becomes large and the electric resistance of the portion provided in the high expansion / contraction portion 20 in the sensor constituent portions 30a and 30b becomes remarkably large, the conduction portions 28a and 28b and the expansion / contraction portion are low. Continuity with the sensor components 30a and 30b provided in the unit 22 is maintained. As a result, the detection of expansion and contraction deformation is maintained by the detection unit 32 provided in the low expansion and contraction unit 22.

Since the high expansion / contraction portion 20 and the low expansion / contraction portion 22 are integrally and continuously formed of the same material, they are easy to manufacture. Since the high expansion / contraction portion 20 and the low expansion / contraction portion 22 are set according to the difference in width dimension, the difference in expansion / contraction deformation between the high expansion / contraction portion 20 and the low expansion / contraction portion 22 can be easily set, for example, another sheet. There is no need to reinforce with and provide a low expansion / contraction portion 22.

The ends of the conductive portions 28a and 28b of the first and second electrodes 16 and 18 to which the first and second wirings 46 and 48 are connected are provided in the low expansion and contraction portion 22 of the base material 38. As a result, when the expansion / contraction sensor 10 expands and contracts in the length direction, the stress due to the deformation acting on the connection portion between the first and second wirings 46 and 48 and the first and second electrodes 16 and 18 is reduced. This prevents problems such as disconnection.

Moreover, the connecting portions of the first and second electrodes 16 and 18 and the first and second wirings 46 and 48 are sandwiched and restrained by the wiring fixing member 50 mounted on the expansion / contraction sensor 10. As a result, when the expansion / contraction sensor 10 expands and contracts in the length direction, the stress acting on the connecting portions of the first and second wirings 46 and 48 is further reduced, and problems such as disconnection are avoided.

The expansion / contraction sensor 10 is attached to two points whose both ends are separated from each other of the detection target (not shown), and detects a change in distance between the two points of the detection target. Here, by providing the expansion / contraction sensor 10 not only with the low expansion / contraction portion 22 but also with the high expansion / contraction portion 20, the expansion / contraction deformation of the entire expansion / contraction sensor 10 is greatly allowed as compared with the case where the whole is a low expansion / contraction portion. The expansion / contraction deformation of the expansion / contraction sensor 10 can be made to follow the change in the distance between the two points to be detected.

FIG. 11 shows the sensor main body 70 constituting the expansion / contraction detection device as the second embodiment of the present invention. The sensor body 70 has a structure in which the first electrode 72 and the second electrode 74 are fixed to both sides of the dielectric layer 14. In the following description, the members and parts substantially the same as those in the first embodiment are designated by the same reference numerals in the drawings, and the description thereof will be omitted.

The first and second electrodes 72 and 74 each include a sensor component 76 that is arranged so as to face each other in the vertical direction to form a detection unit 32, and a conduction unit 28 that extends from the sensor component 76. There is. The first electrode 72 and the second electrode 74 have a plane-symmetrical shape with respect to a plane that passes through the center in the width direction and is orthogonal to the width direction.

In the sensor component 76, the portion fixed to the high expansion / contraction portion 20 of the dielectric layer 14 is the narrow portion 78, and the portion fixed to the low expansion / contraction portion 22 of the dielectric layer 14 is the wide portion 80. Has been done. The wide portion 80 has a larger width dimension than the narrow portion 78 at least in part. Preferably, the width dimension of the wide portion 80 is made larger than the width dimension of the narrow portion 78 in a range of more than half in the length direction of the wide portion 80. More preferably, the width dimension of the wide portion 80 is made larger than the width dimension of the narrow portion 78 in the range of 70% or more in the length direction of the wide portion 80. The area of the wide portion 80 is larger than the area of the narrow portion 78.

The first and second electrodes 72 and 74 are superposed on both surfaces of the dielectric layer 14. The first electrode 72 and the second electrode 74 are arranged in the sensor component 76 so as to face each other in the vertical direction with the dielectric layer 14 interposed therebetween, and the sensors of the first electrode 72 and the second electrode 74 are arranged. The detection unit 32 is configured on the opposite portion of the configuration unit 76. The conductive portion 28a of the first electrode 72 and the conductive portion 28b of the second electrode 74 are arranged at positions separated from each other in the width direction without facing each other in the vertical direction.

According to the sensor main body 70 having a structure according to the present embodiment, the portion of the detection unit 32 provided in the high expansion / contraction portion 20 is made smaller than the portion provided in the low expansion / contraction portion 22. The portion of the detection unit 32 provided in the low expansion / contraction unit 22 has a greater contribution to the detection value of the capacitance of the detection unit 32 than the portion provided in the high expansion / contraction unit 20. Therefore, when the sensor main body 70 is greatly expanded and deformed in the length direction, even if the portion provided in the high expansion and contraction portion 20 in the detection unit 32 is greatly deformed and the capacitance cannot be detected, it can be detected. The influence on the detected value of the entire unit 32 is reduced. As a result, even when the sensor body 70 is significantly stretched and deformed, the stretch and deform can be detected accurately.

FIG. 12 shows a stretch sensor 90 as a third embodiment of a stretch detection device having a structure according to the present invention. In the expansion / contraction sensor 90, the thickness dimension of the first protective layer 94 constituting the base material 92 changes in the length direction.

That is, the first protective layer 94 has a thick portion 96 at one end in the length direction, and the thick portion 96 expands and contracts and deforms in the length direction in response to the action of an external force in the length direction. The amount is smaller than the amount of expansion and contraction deformation in the length direction in the portion outside the thick portion 96. As a result, one end of the base material 92 in which the thick portion 96 is provided is the low expansion / contraction portion 98, and the portion of the base material 92 that is separated from the thick portion 96 in the length direction is formed. It is said to be a high expansion / contraction portion 100. In short, in the expansion / contraction sensor 90 of the present embodiment, the low expansion / contraction portion 98 and the high expansion / contraction portion 100 of the base material 92 are provided according to the difference in the thickness of the base material 92, and the thickness dimension of the low expansion / contraction portion 98 is high. It is made larger than the thickness dimension of the expansion / contraction portion 100.

When the low-stretchable portion and the high-stretchable portion are provided by changing the shape of the base material, the low-stretchable portion 22 and the high-stretchable portion 20 are provided with different width dimensions of the base material 38 as in the first embodiment. On the other hand, as in the present embodiment, the low expansion / contraction portion 98 and the high expansion / contraction portion 100 can be provided with different thickness dimensions of the base material 92.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited by the specific description thereof. For example, in the above-described embodiment, the low-stretch portion and the high-stretch portion of the base material are provided depending on the shape of the base material, but the low-stretch portion and the high-stretch portion have different materials, for example. It can also be provided by. Further, for example, by forming the base material by including the reinforcing body by superimposing another reinforcing body on a part of the base material, the expansion / contraction deformation rate can be adjusted to provide the low expansion / contraction portion. ..

The low expansion / contraction portion and the high expansion / contraction portion can be provided by combining different width dimensions, different thickness dimensions, different materials, and the like. For example, by making the low expansion / contraction portion wide and thick, and making the high expansion / contraction portion narrow and thin, it is possible to set the difference in the expansion / contraction deformation rate between the low expansion / contraction portion and the high expansion / contraction portion.

For example, the amount of expansion and contraction deformation of the base material can be limited by reducing the expansion and contraction rate of the base material by partially or wholly sandwiching the base material with a restraining member.

In the above embodiment, the detection unit 32 is provided only at one end of the base material 38, but for example, the detection unit 32 may be provided at both ends of the base material 38. As can be seen from this, it is also possible to provide a plurality of detection units 32, whereby detection accuracy and reliability can be improved. Further, the detection unit 32 can be continuously provided over substantially the entire length of the base material 38.

In the above embodiment, the detection unit 32 is provided straddling the low expansion / contraction portion 22 and the high expansion / contraction portion 20, but the detection unit 32 is provided only in the low expansion / contraction portion 22 and is provided in the high expansion / contraction portion 20. It doesn't have to be.

The arrangement of the low expansion / contraction portion 22 and the high expansion / contraction portion 20 in the base material 38 is not particularly limited. It may be provided in.

The base material 38 of the above-described embodiment is composed of the dielectric layer 14 and the first and second protective layers 34 and 36, but the first and second protective layers 34 and 36 are omitted and the dielectric material is omitted. The substrate can also be composed of only the layer 14. Further, the sensor main body 12 may be arranged on the second protective layer 36 using the second protective layer 36 as a base material, and in that case, the portion where the sensor main body 12 constitutes a part of the base material ( The dielectric layer 14) of the embodiment may not be provided. Since the electrodes (16, 18, etc.) that are the output parts of the electrical signal are the objects for which the change in electrical resistance is controlled, they can be used as a base material that expands and contracts as described in the above embodiment. It is desirable to grasp without including, but for example, it is possible to positively and partially control the expansion and contraction characteristics of the base material by partially differentizing the thickness and width of the electrodes. In any aspect, the base material including the electrodes can be grasped.

The base material 38 is not necessarily limited to a strip shape, and may be, for example, a substantially square rectangular sheet shape when viewed in the vertical direction.

The detection method of the detection unit is not limited to the exemplified capacitance method. For example, a piezoelectric method that detects expansion and contraction deformation based on the electromotive force due to deformation of the piezoelectric layer, and changes in electrical resistance due to deformation of a conductive elastomer in which a conductive filler is mixed and dispersed in an electrically insulating elastic body. Various known detection methods such as an electric resistance method for detecting expansion and contraction deformation based on the above can be adopted.

The method for forming the dielectric layer 14, the first and second protective layers 34 and 36, and the first and second electrodes 16 and 18 constituting the base material 38 is not particularly limited. For example, the dielectric layer 14 provided with the first and second electrodes 16 and 18 and the first and second protective layers 34 and 36 are formed as independent sheets, and the dielectric layers 14 and the first, The second protective layers 34 and 36 may be overlapped and fixed. Further, for example, the dielectric layer 14, the first and second protective layers 34 and 36, and the first and second electrodes 16 and 18 may be formed in a state of being laminated in an appropriate order by various printing methods. can. The first and second electrodes 16 and 18 are formed on the surface of the dielectric layer 14 by various printing methods, or the first and second electrodes 16 and 18 separately formed as a thin film are formed as a dielectric layer. It can be provided by sticking it to 14.

In the above-described embodiment, the expansion / contraction detection device for detecting the expansion / contraction deformation in the length direction has been described, but for example, the expansion / contraction deformation can be detected in a plurality of directions such as the length direction and the width direction. In the expansion / contraction detection device, attachment portions to the detection target are provided at portions separated from each other in the expansion / contraction detection direction (for example, both end portions as in the above embodiment), and the attachment portions are provided between the attachment portions. At least one high-stretchable portion and one low-stretchable portion are provided in portions that are different from each other in a direction in which the portions are separated from each other (direction in which expansion and contraction deformation is detected). In the above embodiment, it is possible to measure the amount of expansion and contraction deformation, but for example, only the presence or absence of expansion and contraction deformation may be detected.

The expansion / contraction sensor 10 as the expansion / contraction detection device is attached to the detection target via the wiring fixing member 50, but for example, both ends of the expansion / contraction sensor 10 may be directly attached to the detection target. In short, the method of attaching the expansion / contraction detection device to the detection target is not particularly limited. Further, the specific structure of the wiring fixing member 50 is merely an example and can be appropriately changed. Further, the detection target is not limited to the distance between two points of a single member, and for example, by mounting the expansion / contraction sensor 10 so as to hang between the different members, the mutual distance between the different members can be detected. It is possible.

Further, the present invention originally includes all of the inventions described in the following (i) to (x), and the configuration and the action and effect thereof will be added.
The present invention
(I) In a thin-walled base material that can be stretched and deformed in the plane direction, a detection unit is provided that stretches and deforms following the stretch and deformation of the base material and electrically detects the stretch and deformation of the base material. In the expansion / contraction detection device, the base material has a high expansion / contraction portion and a low expansion / contraction portion, and the expansion / contraction deformation rate of the low expansion / contraction portion in the substrate is smaller than that of the high expansion / contraction portion, and the detection is performed. An expansion / contraction detection device whose portion is provided in the low expansion / contraction portion of the substrate,
(Ii) The expansion / contraction detection device according to (i), wherein the detection unit is provided so as to straddle the high expansion / contraction portion and the low expansion / contraction portion of the base material.
(Iii) The expansion / contraction detection device according to (i) or (ii), wherein the high expansion / contraction portion and the low expansion / contraction portion are made of the same material.
(Iv) The expansion / contraction detection device according to any one of (i) to (iii), wherein the width dimension of the low expansion / contraction portion is larger than the width dimension of the high expansion / contraction portion.
(V) The expansion / contraction detection device according to any one of (i) to (iv), wherein the thickness dimension of the low expansion / contraction portion is larger than the thickness dimension of the high expansion / contraction portion.
(Vi) The detection unit has a structure in which detection electrodes are superposed on both sides of the dielectric layer, and the expansion and contraction of the dielectric layer accompanying the expansion and contraction of the base material is based on the change in capacitance. The expansion / contraction detection device according to any one of (i) to (v), which is a capacitance type sensor for detection.
(Vii) The expansion / contraction detection device according to (vi), wherein the dielectric layer is composed of the base material.
(Viii) The output value of the detection signal output by the detection unit corresponding to the expansion and contraction deformation of the base material does not have a maximum value within the range of the expected expansion and contraction deformation of the base material (i) to (vii). The expansion / contraction detection device according to any one of the above,
(Ix) The expansion / contraction detection device according to any one of (i) to (viii), wherein the connection portion of the wiring to the detection unit is arranged in the low expansion / contraction unit.
(X) The expansion / contraction detection device according to (ix), wherein the connection portion includes a wiring fixing member that partially sandwiches and restrains the low expansion / contraction portion in the thickness direction.
Including inventions related to.
In the invention described in (i) above, since the detection unit is provided in the low expansion / contraction portion of the base material having a low expansion / contraction deformation rate, even when the deformation amount of the entire base material is large, the deformation of the portion in which the detection unit is provided is deformed. The amount is suppressed. Therefore, even when the base material is significantly deformed, the detection unit can accurately detect the expansion and contraction deformation of the base material by preventing the detection unit from excessively increasing the electric resistance due to the large deformation.
In the invention described in (ii) above, when the amount of expansion and contraction deformation of the base material is large, the detection unit is also located in the low expansion and contraction portion, so that the amount of expansion and contraction deformation of the entire detection unit is suppressed and detection is performed. Deterioration of detection performance due to excessive deformation of the part is prevented. Further, when the amount of expansion / contraction deformation of the base material is small, the high expansion / contraction portion is deformed relatively large, so that the detection sensitivity can be improved by the detection unit located in the high expansion / contraction portion.
In the invention described in (iii) above, for example, it is possible to integrally form the entire base material provided with the highly stretchable portion and the low stretchable portion.
In the invention described in (iv) above, the low expansion and contraction portion and the high expansion and contraction portion can be set in the base material depending on the difference in width dimension. For example, when the low expansion / contraction portion and the high expansion / contraction portion are formed of the same material as in the above aspect (iii), the difference in the expansion / contraction ratio between the low expansion / contraction portion and the high expansion / contraction portion is easily set by the difference in the width dimension. be able to. Further, for example, when a plurality of detection portions such as an electrode layer and a dielectric layer are laminated, the high expansion / contraction portion and the low expansion / contraction portion do not affect the laminated structure due to the dimensions in the width direction orthogonal to the stacking direction. The expansion and contraction part can be set.
In the invention described in (v) above, a low expansion / contraction portion and a high expansion / contraction portion can be set in the base material depending on the difference in thickness and dimension. For example, when the low-stretchable portion and the high-stretchable portion are formed of the same material as in the third aspect, the difference in the stretch ratio between the low-stretchable portion and the high-stretchable portion is easily set by the difference in the thickness dimension. be able to.
In the invention described in (vi) above, the capacitance between the detection electrodes facing each other across the dielectric layer changes due to the deformation of the detection electrode and the dielectric layer due to the expansion and contraction deformation of the base material. Based on the electrical output of this change in capacitance, the amount of expansion and contraction deformation of the base material can be accurately detected.
In the invention described in (vii) above, the number of parts can be reduced because the base material also serves as a dielectric layer.
In the invention described in (viii) above, for example, it is possible to prevent a measurement error of expansion and contraction deformation caused by the output value of the detection signal being the same on both sides of the maximum value.
In the invention described in (ix) above, it is difficult to allow large deformation of the connection portion of wiring such as an output lead wire because it is soldered or a connector is provided. Therefore, by providing the connection portion of the wiring in the low expansion / contraction portion where the expansion / contraction deformation is suppressed, the stress acting on the connection portion of the wiring at the time of expansion / contraction deformation of the base material is reduced, and the reliability and durability are improved. ..
In the invention described in (x) above, the low expansion / contraction portion is restrained by the wiring fixing member, so that the expansion / contraction deformation of the detection portion is further reduced at the connection portion of the wiring. Therefore, the stress acting on the connection portion of the wiring when the base material is deformed is further reduced, and the durability is further improved.

10,90 stretch sensor (stretch detection device)
12,70 Sensor body 14 Dielectric layer 16,72 First electrode 18,74 Second electrode 20,100 High expansion / contraction part 22,98 Low expansion / contraction part 24 Widening part 26 Inclined part 28 Conducting part 30,76 Sensor component part 32 Detection unit 34,94 First protective layer 36 Second protective layer 38,92 Base material 40 First conduction hole 42 Second conduction hole 44 Locking hole 46 First wiring 48 Second wiring 50 Wiring Fixing member 52 First fixing member 54 Second fixing member 56 Pressing part 58 First fitting part 60 Second fitting part 62 First connecting electrode 64 Second connecting electrode 66 Locking protrusion 68 Mounting member 78 Narrow part 80 Wide part 96 Thick part

Claims (10)

A stretch detection device provided with a detection unit that electrically detects the stretch deformation of the base material by stretching and deforming according to the stretch deformation of the base material in a thin-walled base material that can be stretched and deformed in the plane direction. And
The detection unit has a structure in which detection electrodes are superposed on both sides of the dielectric layer, and static electricity detects expansion and contraction of the dielectric layer due to expansion and contraction of the base material based on a change in capacitance. While it is said to be a capacitive sensor,
The base material has a high expansion / contraction portion and a low expansion / contraction portion, and the expansion / contraction deformation rate of the low expansion / contraction portion in the substrate is made smaller than that of the high expansion / contraction portion.
The detection electrode is provided on the highly stretchable portion in which the base material extends linearly in the length direction with a substantially constant width dimension and on the end side in the length direction of the highly stretchable portion. Expansion / contraction detection is provided so as to straddle the low expansion / contraction portion extending in a cross-sectional shape larger than the portion, and the detection electrode extends only from the low expansion / contraction portion to an intermediate portion in the length direction of the high expansion / contraction portion. Device. The expansion / contraction detection device according to claim 1 , wherein the dielectric layer is made of the base material. The expansion / contraction detection device according to claim 1 or 2, wherein the high expansion / contraction portion and the low expansion / contraction portion are made of the same material. The expansion / contraction detection device according to any one of claims 1 to 3, wherein the width dimension of the low expansion / contraction portion is larger than the width dimension of the high expansion / contraction portion. The expansion / contraction detection device according to any one of claims 1 to 4, wherein the thickness dimension of the low expansion / contraction portion is larger than the thickness dimension of the high expansion / contraction portion. Any one of claims 1 to 5 , wherein the output value of the detection signal output by the detection unit in response to the expansion and contraction deformation of the base material does not have a maximum value in the range of the assumed expansion and contraction deformation of the base material. The expansion / contraction detection device described in. The expansion / contraction detection device according to any one of claims 1 to 6 , wherein the connection portion of the wiring to the detection unit is arranged in the low expansion / contraction unit. The expansion / contraction detection device according to claim 7 , wherein the connection portion includes a wiring fixing member that partially sandwiches and restrains the low expansion / contraction portion in the thickness direction. The expansion / contraction detection device according to any one of claims 1 to 8, wherein the width dimension between the facing surfaces of the detection electrodes laminated on both sides of the dielectric layer is smaller than that of the low expansion / contraction portion in the high expansion / contraction portion. .. The expansion / contraction detection device according to any one of claims 1 to 9, wherein the wiring conducted to the detection electrode is connected to the low expansion / contraction portion.